Protection from spinal cord ischemia-reperfusion damage with alpha-lipoic acid preconditioning in an animal model

Oxidative stress following spinal cord injury: From molecular mechanisms to therapeutic targets

Spinal cord injury (SCI) is a medical condition that results from severe trauma to the central nervous system; it imposes great psychological and economic burdens on affected patients and their families. The dynamic balance between reactive oxygen species (ROS) and antioxidants is essential for maintaining normal cellular physiological functions. As important intracellular signaling molecules, ROS regulate numerous physiological activities, including vascular reactivity and neuronal function. However, excessive ROS can cause damage to cellular macromolecules, including DNA, lipids, and proteins; this damage eventually leads to cell death. This review discusses the mechanisms of oxidative stress in SCI and describes some signaling pathways that regulate oxidative injury after injury, with the aim of providing guidance for the development of novel SCI treatment strategies.

The comparison of alpha lipoic acid with methylprednisolone and sucralfate in subacute wound healing corrosive esophagus-induced rats: An experimental study

Background

This study aims to compare methylprednisolone frequently used in the therapeutic practices of corrosive esophagus burns, sucralfate, a protective material of mucosal surfaces, and alpha lipoic acid, the most potent antioxidant in a rat model.

Methods

A total of 40 female Sprague-Dawley rats were used in this study. The rats were equally divided into control, alpha lipoic acid, methylprednisolone, and sucralfate groups (n=10). A corrosive esophagus burn was created by using 10% pH:12 sodium hydroxide. No treatment was applied to the control group, and each group was given their own treatment. The treatment was continued regularly until the eighth day, when they were sacrificed. The corrosive esophagus burn lines were removed and tissue sections were stained with hematoxylin and eosin.

Results

The difference in ulceration in the group treated with alpha lipoic acid was significant, compared to the other groups. The most excellent complete epithelialization and complete re-epithelialization were observed in the alpha lipoic acid group. The difference between the groups was significant, with complete re-epithelialization being the lowest in the control and methylprednisolone groups (42.9% and 12.5%, respectively) and the highest in the alpha lipoic acid group (77.8%). In terms of ulceration and re-epithelialization, comparable values were found in the alpha lipoic acid group. The main difference was that the inflammation levels in the sucralfate group were lower and more favorable than the other groups in this period. The glutathione level was significantly higher in the alpha lipoic acid group and decreased the tissue hydroxyproline level.

Conclusion

Alpha lipoic acid reduces esophageal ulceration, severity and prevalence of inflammation, severity and prevalence of fibrosis, decreases tissue damage by increasing blood glutathione level, and also reduces stricture in corrosive esophagus burns in rats.

α-Lipoic Acid, an Organosulfur Biomolecule a Novel Therapeutic Agent for Neurodegenerative Disorders: An Mechanistic Perspective

Lipoic acid (α-LA) (1,2-dithiolane3-pentanoic acid (C₈H₁₄O₂S₂) is also called thioctic acid with an oxidized (disulfide, LA) and a reduced (di-thiol: dihydro-lipoic acid, DHLA) form of LA. α-LA is a potent anti-oxidative agent that has a significant potential to treat neurodegenerative disorders. α-LA is both hydrophilic and hydrophobic in nature. It is widely distributed in plants and animals in cellular membranes and in the cytosol, which is responsible for LA's action in both the cytosol and plasma membrane. A systematic literature review of Bentham, Scopus, PubMed, Medline, and EMBASE (Elsevier) databases was carried out to understand the Nature and mechanistic interventions of the α-Lipoic acid for central nervous system diseases. Moreover, α-LA readily crosses the blood-brain barrier, which is a significant factor for CNS activities. The mechanisms of α-LA reduction are highly tissue-specific. α-LA produces its neuroprotective effect by inhibiting reactive oxygen species formation and neuronal damage, modulating protein levels, and promoting neurotransmitters and anti-oxidant levels. Hence, the execution of α-LA as a therapeutic ingredient in the therapy of neurodegenerative disorders is promising. Finally, based on evidence, it can be concluded that α-LA can prevent diseases related to the nervous system.

Histological Findings After Aortic Cross-Clamping in Preclinical Animal Models

Spinal cord ischemic injury and paralysis are devastating complications after open surgical repair of thoracoabdominal aortic aneurysms. Preclinical models have been developed to simulate the clinical paradigm to better understand the neuropathophysiology and develop therapeutic treatment. Neuropathological findings in the preclinical models have not been comprehensively examined before. This systematic review studies the past 40 years of the histological findings after open surgical repair in preclinical models. Our main finding is that damage is predominantly in the grey matter of the spinal cord, although white matter damage in the spinal cord is also reported. Future research needs to examine the neuropathological findings in preclinical models after endovascular repair, a newer type of surgical repair used to treat aortic aneurysms.

Effects of Lipoic Acid on Ischemia-Reperfusion Injury

Ischemia-reperfusion (I/R) injury often occurred in some pathologies and surgeries. I/R injury not only harmed to physiological functions of corresponding organ and tissue but also induced multiple tissue or organ dysfunctions (even these in distant locations). Although the reperfusion of blood attenuated I/R injury to a certain degree, the risk of secondary damages was difficult to be controlled and it even caused failures of these tissues and organs. Lipoic acid (LA), as an endogenous active substance and a functional agent in food, owns better safety and effects in our body (e.g., enhancing antioxidant activity, improving cognition and dementia, controlling weight, and preventing multiple sclerosis, diabetes complication, and cancer). The literature searching was conducted in PubMed, Embase, Cochrane Library, Web of Science, and SCOPUS from inception to 20 May 2021. It had showed that endogenous LA was exhausted in the process of I/R, which further aggravated I/R injury. Thus, supplements with LA timely (especially pretreatments) may be the prospective way to prevent I/R injury. Recently, studies had demonstrated that LA supplements significantly attenuated I/R injuries of many organs, though clinic investigations were short at present. Hence, it was urgent to summarize these progresses about the effects of LA on different I/R organs as well as the potential mechanisms, which would enlighten further investigations and prepare for clinic applications in the future.

Resveratrol against lung injury in an ischemia/reperfusion model of abdominal aortic rupture

Background

The aim of this study was to examine the effects on the lungs of ischemia/reperfusion injury in a ruptured abdominal aortic aneurysm model in rats and to investigate the potential protective effects of resveratrol.

Methods

Thirty-two male Sprague-Dawley rats were randomly divided into four groups: control, ischemia/reperfusion, sham (ischemia/ reperfusion + solvent/dimethyl sulfoxide), and ischemia/reperfusion + resveratrol. In the groups subjected to ischemia/reperfusion, following 60-min shock to the abdominal aorta, vascular clamps were attached from the levels of the infrarenal and iliac bifurcation. A total of 60-min ischemia was applied, followed by 120-min reperfusion. In the ischemia/ reperfusion + resveratrol group, intraperitoneal 10 mg/kg resveratrol was administered 15 min before ischemia and immediately after reperfusion. Malondialdehyde, glutathione, and catalase levels were analyzed and histopathological examination of the lung tissues was performed.

Results

Malondialdehyde levels increased in the ischemia/reperfusion and ischemia/reperfusion + dimethyl sulfoxide groups, compared to the control group, while catalase levels decreased, and no significant difference was observed in the glutathione levels. Malondialdehyde levels decreased with the administration of resveratrol, while glutathione levels increased, and catalase levels remained unchanged. The increased inflammation in interstitial spaces, thickening in the alveolar septal walls, increased numbers of cleaved caspase-3 apoptotic pneumocytes, and increased histopathological lung damage scores observed in the ischemia/reperfusion and ischemia/reperfusion + dimethyl sulfoxide groups improved with the application of resveratrol.

Conclusion

These findings suggest that resveratrol may exhibit a protective effect in preventing acute lung injury developing due to ischemia/reperfusion in ruptured abdominal aortic aneurysm surgery by reducing oxidative damage.